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  • Open Access

    ARTICLE

    Effect of Phenolation, Lignin-Type and Degree of Substitution on the Properties of Lignin-Modified Phenol-Formaldehyde Impregnation Resins: Molecular Weight Distribution, Wetting Behavior, Rheological Properties and Thermal Curing Profiles

    Marion Thébault1, Larysa Kutuzova2, Sandra Jury1, Iris Eicher1, Edith-Martha Zikulnig-Rusch1, Andreas Kandelbauer2,*

    Journal of Renewable Materials, Vol.8, No.6, pp. 603-630, 2020, DOI:10.32604/jrm.2020.09616

    Abstract Here, the effects of substituting portions of fossil-based phenol in phenol formaldehyde resin by renewable lignin from two different sources are investigated using a factorial screening experimental design. Among the resins consumed by the wood-based industry, phenolics are one of the most important types used for impregnation, coating or gluing purposes. They are prepared by condensing phenol with formaldehyde (PF). One major use of PF is as matrix polymer for decorative laminates in exterior cladding and wet-room applications. Important requirements for such PFs are favorable flow properties (low viscosity), rapid curing behavior (high reactivity) and… More >

  • Open Access

    ARTICLE

    Renewable Bis-benzoxazine Monomers from Lignin Derivatives: Synthesis, Characterization and Studies on Curing Behavior

    CHUNYAN LIU*, YUNHE LIU, ZIHAN PAN, QIUTING LI, HAN XU, TAO LIU

    Journal of Polymer Materials, Vol.36, No.1, pp. 87-99, 2019, DOI:10.32381/JPM.2019.36.01.7

    Abstract In this work, a series of novel lignin-based bis-benzoxazine monomers were efficiently synthesized by the reaction of renewable phenols: guaiacol, vanillyl alcohol, eugenol, vanillin with ethylene diamine and paraformaldehyde. The chemical structures of these lignin-based bis-benzoxazine monomers were confirmed by 1H-NMR, 13C-NMR and FTIR, indicating the formation of benzoxazine ring. The obtained bis-benzoxazine monomers were cured via thermal treatment. The curing behavior of these lignin-based bis-benzoxazine monomers were compared and analyzed via differential scanning calorimetry (DSC), showing that Va-e possessed higher ring-opening polymerization activity than G-e, while E-e and V-e had lower curing activity than G-e. More >

  • Open Access

    ARTICLE

    Structural Characterization and Antioxidant Activity of Lignin Extracted from Ficus Carica L.

    Ibtissem Moussa1,2, Ramzi Khiari1,3,4,*, Ali Moussa2, Gérard Mortha4, Mohamed Farouk Mhenni1

    Journal of Renewable Materials, Vol.7, No.4, pp. 345-354, 2019, DOI:10.32604/jrm.2019.04011

    Abstract The most abundant phenolic biopolymer in the biosphere is the lignin. This phenolic biopolymer commonly exists in combination with polysaccharides and other cell wall components. In this study, the solvent system dioxane-water is used to extract lignin, which is considered as unaltered native lignin. The dioxane lignin extracted from fig stems was characterized regarding to its structural feature, quantification of its functional groups, molecular weight, and evaluation of its thermal properties. Purity and molecular weight distribution of the studied lignin indicated that isolated lignin contained a low amount of sugar (c.a. 19%) and had a More >

  • Open Access

    ARTICLE

    Liquefaction of Kraft Lignin at Atmospheric Pressure

    Silvia Helena Fuentes da Silva1, Patricia Soares Bilhalva dos Santos2, Darci Alberto Gatto3, Maria Angeles Andres1, Itziar Egüés1,*

    Journal of Renewable Materials, Vol.7, No.6, pp. 527-534, 2019, DOI:10.32604/jrm.2019.04291

    Abstract Kraft lignin was liquefied using polyethylene glycol #400 (PEG) and glycerol (G) in a weight ratio of 80/20 (w/w) and sulphuric acid (SA) as catalyst under atmospheric pressure at 160ºC. The three independent variables: reaction time (60, 80 and 100 min), percentage of lignin (15, 20 and 25%, w/w), and catalyst concentration (0, 3 and 6%, w/w), were varied resulting in 27 experimental runs. The effect of these reaction conditions on the properties of the polyols was evaluated. The statistical analysis showed that only “the percentage of lignin” did not influence the properties of the More >

  • Open Access

    ARTICLE

    Polyurethanes from Kraft Lignin without Using Isocyanates

    F.J. Santiago-Medina1, M.C. Basso1, A. Pizzi1,2,*, L. Delmotte3

    Journal of Renewable Materials, Vol.6, No.4, pp. 413-425, 2018, DOI:10.7569/JRM.2017.634172

    Abstract The reaction of a desulphurized kraft lignin with hexamethylene diamine and dimethyl carbonate has allowed the development of isocyanate-free polyurethane resins. The present research work is based on previous studies made with hydrolyzable and condensed tannins, but takes advantage of the higher number of hydroxyl groups present in lignin and their different aliphatic and aromatic character. The obtained materials were analyzed by Fourier transform infrared (FTIR) spectroscopy, matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry and solid-state cross-polarization/magic angle spinning (CP MAS) 13 C nuclear magnetic resonance (NMR), which have revealed the presence of urethane More >

  • Open Access

    ARTICLE

    Valorization of Kraft Lignin as Thickener in Castor Oil for Lubricant Applications

    A. M. Borrero-López1, F. J. Santiago-Medina1, C. Valencia1,2*, M. E. Eugenio3, R. Martin-Sampedro3, J. M. Franco1,2

    Journal of Renewable Materials, Vol.6, No.4, pp. 347-361, 2018, DOI:10.7569/JRM.2017.634160

    Abstract It is known that large amounts of residual lignin are generated in the pulp and paper industry. A new alternative for Kraft lignin valorization, which consists of first a chemical modification using a diisocyanate and then the efficient dispersion in castor oil to achieve stable gel-like systems, is proposed in this work. Rheological properties and microstructure of these materials were determined by means of small amplitude oscillatory shear tests and viscous flow measurements and atomic force microscopy observations, respectively. Moreover, both standardized penetration tests and tribological assays, usually performed in the lubricant industry, were carried More >

  • Open Access

    ARTICLE

    Tuning Intermolecular Interaction Between Lignin and Carbon Nanotubes in Fiber Composites – A Combined Experimental and Ab-InitioModeling Study

    Jan Badorrek1,2, Michael Walter3,4,*, Marie-Pierre Laborie1,2,*

    Journal of Renewable Materials, Vol.6, No.3, pp. 325-335, 2018, DOI:10.7569/JRM.2017.634183

    Abstract Doping lignin with carbon nanotubes is a promising strategy for cost-effective high-performance carbon fibers. We investigate the intermolecular interaction potential of CNT and organosolv lignin with two main approaches. Experimentally, oxidized purified multiwalled carbon nanotubes (MWCNTs) and beech organosolv lignins and derivatives are analyzed with their Hansen solubility parameters (HSPs) to assess their mutual compatibility. Theoretically, dispersion-corrected density functional theory simulations of the interaction between model molecules and single-walled carbon nanotubes reveal the source of interactions. We find that oxidation enables and enhances the interaction between carbon nanotubes and organosolv lignin experimentally, which is in More >

  • Open Access

    ARTICLE

    Application of Prunus amygdalus By-products in Eco-friendly Dyeing of Textile Fabrics

    Ibtissem Moussa1, Noureddine Baaka1, Ramzi Khiari1,2,3*, Ali Moussa4, Gérard Mortha3, Mohamed Farouk Mhenni1

    Journal of Renewable Materials, Vol.6, No.1, pp. 55-67, 2018, DOI:10.7569/JRM.2017.634141

    Abstract Natural dyes have become an interesting subject of study because of their better ecological properties in comparison to their synthetic counterparts. This article concerns the dyeing of wool, silk, and polyamide fabrics with natural dyes extracted from almond shells and stems. The developed method of dyeing by these extracts is interesting and very attractive for several reasons: firstly, the extracts used are the black liquor discharged from the industries of delignification, which is a chemical process for removing lignin from agricultural wastes to produce a cellulosic fiber; (ii) these natural dyes are renewable and available More >

  • Open Access

    ARTICLE

    Polycondensation Resins by Lignin Reaction with (Poly) amines

    F. J. Santiago-Medina1, A. Pizzi1, 2*, M. C. Basso1, L. Delmotte3, S. Abdalla2

    Journal of Renewable Materials, Vol.5, No.5, pp. 388-399, 2017, DOI:10.7569/JRM.2017.634142

    Abstract The reaction of a desulphurized kraft lignin with hexamethylene diamine as a model of a polyamine has been investigated. For this purpose, guaiacol was also used as a lignin model compound and treated under similar conditions. Solid state CP-MAS 13C NMR, FTIR and MALDI-TOF spectroscopy studies revealed that polycondensation compounds leading to resins were obtained by the reaction of the amines with the phenolic and aliphatic hydroxy groups of lignin. Simultaneously a second reaction leading to the formation of ionic bonds between the same groups occurred. These new reactions have been clearly shown to involve More >

  • Open Access

    ARTICLE

    Biomatrix from Stipa tenacissima L. and its Application in Fiberboard Using Date Palm Rachis as Filler

    Mohamed Ammar1, Ramzi Khiari2,3,4*, Mohamed Naceur Belgacem3,4*, Elimame Elaloui1

    Journal of Renewable Materials, Vol.5, No.2, pp. 116-123, 2017, DOI:10.7569/JRM.2016.634136

    Abstract The present study investigated the preparation of biomatrices from Stipa tenacissima L. and its valorization for fiberboard application. Resins were produced by extracting lignin from the Stipa tenacissima L. black liquor by soda process and combining it with glyoxal as crosslinking agent to produce lignin-glyoxal-resin (LGR). The matrix was characterized by several methods, such as FTIR and ATG/ATD, and then mixed with date palm rachis as reinforcing fibers in different proportions of 30 and 50% (w/w with respect to the matrix) to produce biodegradable composite materials. Then, their thermal and mechanical properties were determined, using More >

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